1. Field of the Invention
The present invention relates to a slot-in disc drive, and in particular to a disc loading device for use in a slot-in optical disc drive for receiving optical discs of different sizes while unloading other objects inserted into the drive.
2. Description of the Prior Art
Slot-in optical disc drives allow users to conveniently load and unload optical discs. Slot-in optical disc drives can be implemented in various electronic devices, for example notebook computers and car CD players. As for the operation of these disc drives, rollers or other means are used to apply force to the circular periphery of the optical disc, thereby loading or unloading optical discs.
Conventional slot-in optical disc drives have disadvantageous characteristics. For example, if a thin foreign body, such as an ID card, credit card, or phone card, is mistakenly inserted into the slot instead of an optical disc, the drive's sensor may fail to detect its presence. Subsequently, the foreign body may be jammed into the device and damage the disc drive when another optical disc or object is inserted.
Many ideas have been proposed to solve this problem. In the prior art, opposed-mode sensors, for example photo-interrupters, are usually used to detect optical discs. The opposed-mode sensors transmit signals to the control unit of the disc drive indicating when the periphery of the disc reaches the sensors. The disc drive can then function in accordance with these signals. However, if many opposed-mode sensors are used to discriminate between optical discs and other objects, the structure of the drive becomes complex and costly. On the other hand, if only a few opposed-mode sensors are disposed in the disc drive, the discrimination between optical discs and other objects cannot be performed accurately. In addition, it is possible for a user to insert an optical disc or other object into the disc drive at an angle, which also can result in inaccurate discrimination.
Accordingly, there is a need to develop an optical disc drive without these disadvantages.
The present invention provides a novel slot-in optical disc drive that effectively solves the problems mentioned above.